1. Field of the Invention
This invention relates to a continuous electrolytic ion water producing apparatus which electrolyzes water such as city water to continuously produce alkali ion water and acid ion water, and more particularly to a controlling apparatus which controls a continuous electrolytic ion water producing apparatus of the type mentioned so that the electrolyzing capacity may be kept fixed against a variation of the flow rate, the quality of water or the like.
2. Description of the Related Art
A continuous electrolytic ion water producing apparatus which applies a dc voltage between a pair of positive and negative electrodes in drinking water such as city water to electrolyze the drinking water to directly produce alkali ion water and acid ion water is already known. Alkali ion water is used to improve the acid physical constitution, as necessary due to eating habits of moderns principally depending upon meat, while acid ion water is used to wash the surface of the human body and so forth for make-up.
The electrolyzing capacity of an electrolytic cell of an electrolytic ion water producing apparatus of the type mentioned, that is, the hydrogen ion exponent (pH) value of electrolytic ion water produced, depends much upon the flow rate through the electrolytic cell, the electric conductivity, temperature and quality of water supplied to the electrolytic cell and so forth. Various countermeasures for adjusting the electrolyzing capacity of an electrolytic cell have been proposed, and one of the countermeasures is to change over the voltage tap of a power source transformer to adjust the dc supply voltage among a plurality of stages. Another countermeasure is to vary the flow rate of water by means of a flow rate adjusting valve.
By the way, a conventional electrolytic ion water producing apparatus is normally constructed such that a user can manually change over the voltage tap of a power source transformer in accordance with flow rate or the quality of water to roughly adjust the electrolyzing capacity of the electrolytic cell when the electrolytic ion water producing apparatus is in use. Here, the flow rate varies in one of time zones used, and also the temperature of water varies over a comparatively wide range depending on the season and the time. However, in order to keep the electrolyzing capacity fixed against variation, fine adjustment of the flow rate cannot be avoided, making manual operation by the user very complicated. Further, since the adjustment depends much upon judgment of the user it is difficult to always obtain the desired PH value of electrolytic ion water. Accordingly, it is desired to control the dc power supply to the electrolytic cell in a stepless manner to control the electrolyzing capacity of the electrolytic cell automatically to a fixed value against a variation of the flow rate or the quality of water.
A solution to the problem is disclosed, for example, in Japanese Utility Model Laid-Open Application No. 1-163494. According to the proposed solution, electrolytic current is adjusted to one of a plurality of stages by manual operation of an electrolyzing strength adjusting switch. Further, according to the proposed electrolytic ion water producing apparatus, electrolytic current supplied to the electrolytic cell is detected and controlled so that the value thereof coincides with a current value set by manual selective operation of the electrolyzing strength adjusting switch.
With the proposed solution, however, since an electrolytic current is controlled to one of a plurality of stages in response to manual operation of the electrolyzing strength adjusting switch, when the flow rate or the quality of water varies, the electrolyzing capacity cannot be adjusted appropriately against such variation.